Large computer clusters run large amounts of jobs, for instance, scheduled by an orchestrator. For example, a Map-reduce configuration or a DUCC (Distributed UIMA Computing Cluster) cluster may run hundreds of jobs. Each of these jobs may be created, may get more computing resources (e.g., number of processes or machines), may get fewer computing resources, and may terminate. Tools for monitoring the scheduling and the behavior of those jobs typically show an instantaneous view the amount of resources each job consumes at a given point in time. This is useful for administrators to see the overall occupancy of the cluster, and for the user, to see how many resources (e.g., machines) are given to their job(s). However, these traditional tools usually show snapshots of the current load balancing of jobs across the cluster. The creation, termination, expansion and contraction of jobs can be very dynamic and transient, making it difficult to observe and understand this kind of behavior without showing the evolution over time.
An example of a traditional visualization includes “stacked graphs” that could be used to illustrate the contribution over time of each job. However, this visualization type suffers from the effect that the position of the entity shown at the top layer varies wildly, making it hard to assess the contribution by this top entity.
While the stacked graphs are arranged by “gravity” (all layers are stacked on top of each other, as much as possible downwards), another type of visualization referred to as ThemeRivers, lets the different layers gravitate towards a center horizontal axis. ThemeRivers is described in http colon-slash-slash (://) www dot (.) ifs dot (.) tuwien dot (.) ac dot (.) at slash (/) ˜silvia slash (/) wien slash (/) vu-infovis slash (/) references slash (/) havre-ieeeinfovis00 dot (.) pdf. This visualization suffers from the same problem, in that the outer layers suffer from a possibly wild variation in positions, as they are determined by the heights of the layers near the center. Inspecting the evolution of an individual layer can be tedious, especially near the outer layers.
In yet another mechanism, Michael Ogawa in http colon slash slash (://) vis dot (.) cs dot (.) ucdavis dot (.) edu slash (/) papers slash (/) softvis_storylines dot (.) pdf, draws participants of a software project over time as lines. However, these lines are only added to existing lines, similar to RiverThemes, making it hard to follow particular lines.